4.1
The
monitoring results for 1-hour TSP and 24-hour TSP are summarized in Table 4.1 and 4.2 respectively. Graphical
presentations of 1-hour and 24-hour TSP monitoring results are shown in Appendices B
and C respectively.
Table 4.1 Summary Table of 1-hour TSP Monitoring
Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action
Level, µg/m3 |
Limit
Level, µg/m3 |
|
|
Average |
Range |
||||
|
December 2013 |
AMS1 |
125 |
27 - 254 |
381 |
500 |
|
AMS4 |
139 |
36 - 245 |
352 |
||
|
January 2014 |
AMS1 |
100 |
14 - 226 |
381 |
|
|
AMS4 |
125 |
47 - 259 |
352 |
||
|
February 2014 |
AMS1 |
43 |
12 - 74 |
381 |
|
|
AMS4 |
44 |
15 - 99 |
352 |
||
Table 4.2 Summary
Table of 24-hour TSP Monitoring Results during the Reporting Period
|
Month |
Monitoring Station |
Concentration (µg/m3) |
Action
Level, µg/m3 |
Limit
Level, µg/m3 |
|
|
Average |
Range |
||||
|
December 2013 |
AMS1 |
140 |
24 – 260 |
170 |
260 |
|
AMS4 |
86 |
17 - 140 |
171 |
||
|
January 2014 |
AMS1 |
114 |
66 – 207 |
170 |
|
|
AMS4 |
108 |
67 - 131 |
171 |
||
|
February 2014 |
AMS1 |
81 |
12 - 177 |
170 |
|
|
AMS4 |
74 |
17 - 117 |
171 |
||
4.2
According
to our field observations, the major dust source identified at the designated
air quality monitoring stations in the reporting period are as follows:
Table
4.3 Observation at Dust Monitoring
Stations
|
Monitoring Station |
Major
Dust Source |
|
AMS1 |
1) Exhaust
from marine traffic 2) Other
construction site nearby |
|
AMS4 |
N/A |
4.3
The
wind data monitoring results were attached in the Monthly EM&A Reports
4.4
The
noise monitoring results are summarized in
Table 4.4. Graphical presentations of noise monitoring are shown in
Appendix D.
Table 4.4 Summary
Table of Noise
Monitoring Results during the Reporting Period
|
Month |
Monitoring Station |
Noise Level, Leq (30min)
dB(A) |
Limit
Level |
|
|
Average |
Range |
|||
|
December 2013 |
NMS1 |
70 |
68 – 71 |
75 dB(A) |
|
NMS4 |
62 |
58 – 65 |
||
|
January 2014 |
NMS1 |
68 |
66 – 71 |
|
|
NMS4 |
62 |
59 – 63 |
||
|
February 2014 |
NMS1 |
70 |
67 – 72 |
|
|
NMS4 |
61 |
55 – 64 |
||
Remark:
+3dB(A) Façade correction included
4.5
According
to our field observations, the major noise source identified at the designated
noise monitoring stations in the reporting period are as follows:
Table 4.5 Observation
at Noise
Monitoring Stations
|
Monitoring Station |
Major
Noise Source |
|
NMS1 |
Air
traffic & marine traffic noise |
|
NMS4 |
Air
traffic & marine traffic noise |
4.6
The graphical
presentation of water quality at the monitoring stations is shown in Appendix E.
4.7
Water
quality impact sources during the water quality monitoring were the
construction activities of the Contract, nearby construction activities by
other parties and near by operating vessels by other
parties.
Summary of survey effort and dolphin sightings
4.8
During the period of December
2013 to February 2014, six sets of systematic line-transect vessel
surveys were conducted to cover all transect lines in WL survey area twice per
month.
4.9
From these surveys, a total of 192.30
km of survey effort was collected, with 86.2% of the total survey effort being conducted
under favourable weather conditions (i.e. Beaufort
Sea State 3 or below with good visibility). The total survey effort conducted on primary
lines was 125.70 km, while the effort on secondary lines was 66.60
km. Survey effort conducted on
primary and secondary lines were both considered as on-effort survey data.
Summary table of the survey effort is shown in Appendix I of
Appendix F.
4.10
During the six
sets of monitoring surveys in December 2013 to February 2014,
a total of 36 groups of 145
Chinese White Dolphins were sighted.
All except six sightings were made during on-effort search.
Twenty-three on-effort sightings were made on primary
lines, while another seven on-effort sightings were made on secondary
lines. Summary table of the dolphin sightings is
shown in Appendix II of Appendix F.
Distribution
4.11
Distribution of dolphin sightings made during
monitoring surveys in December 2013 to February 2014
is shown in Figure 1 of Appendix F. The dolphin groups were evenly distributed
throughout the WL survey area, with higher concentrations near Kai Kung Shan.
The only areas where dolphins were rarely sighted included the northern end of
the survey area as well as the waters between Tai O and Yi O.
4.12
Notably, only one sighting was made along the
HKLR09 alignment in WL survey area during the present quarter (Figure 1 of Appendix F). It appeared that general shift in dolphin
distribution further south of the WL survey area in the present quarter, and they
rarely occurred at the juncture between NWL and WL survey areas.
The few dolphin groups sighted in the vicinity of HKLR09 alignment were mainly
small groups of dolphins. (Figure
2 of Appendix
F)
Encounter rate
4.13
During the three-month impact phase monitoring
period, the encounter rates of Chinese White Dolphins deduced from the survey
effort and on-effort sighting data from the primary transect lines under favourable conditions (Beaufort 3 or below) from West Lantau survey area are shown in Table 4.6. The average
encounter rates deduced from the six sets of surveys from December
2013 to February 2014 were also compared with the ones deduced
from the baseline monitoring period (September – November 2011) (Table 4.7).
4.14
In WL survey area, the average dolphin
encounter rates in the present three-month study period was either slightly higher (in
STG) or similar to (in ANI) the ones recorded in the 3-month baseline
period respectively, indicating the dolphin usage during this impact phase
monitoring period in this survey area did not show any obvious change when
compared to the baseline phase.
Table 4.6 Dolphin encounter rates (sightings per 100 km of
survey effort) during the impact monitoring period (December 2013 – February 2014)
|
Survey Area |
Dolphin Monitoring |
Encounter rate (STG) |
Encounter rate (ANI) |
|
Primary Lines Only |
Primary Lines Only |
||
|
West Lantau |
9.7 |
67.6 |
|
|
Set 2
(December 20, 2013) |
20.1 |
50.4 |
|
|
Set 3 |
18.8 |
32.9 |
|
|
Set 4 |
10.5 |
21.1 |
|
|
Set 5 |
29.4 |
135.1 |
|
|
Set 6 |
19.6 |
53.8 |
Table 4.7 Comparison of average dolphin encounter rates from
impact monitoring period (December
2013 –
February 2014) and baseline monitoring period
(September-November 2011)
|
|
(no. of on-effort dolphin sightings per 100 km of survey effort) |
Encounter rate (ANI) (no. of dolphins from all
on-effort sightings per 100 km of survey effort) |
||
|
December 2013
- February 2014 |
September- November 2011 |
December 2013 - February
2014 |
September- November 2011 |
|
|
West Lantau |
18.01 ± 7.24 |
16.43 ± 7.70 |
60.12 ± 40.18 |
60.50 ± 38.47 |
(Note:
the encounter rates deduced from the baseline monitoring period have been
recalculated based only on the survey effort and on-effort sighting data made
along the primary transect lines under favourable
conditions)
4.15 A one-way ANOVA was conducted to examine whether there were any significant differences in the average encounter rates between the baseline and impact monitoring periods. For the comparison between the baseline period and the present quarter (fourth quarter of the impact phase), the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.723 and 0.987 respectively. Therefore, no significant difference in dolphin encounter rate was detected between the baseline period and the present quarter.
4.16 Another comparison was made between the baseline period and the cumulative quarters in the impact phase (i.e. first four quarters of the impact phase), and the p-value for the differences in average dolphin encounter rates of STG and ANI were 0.784 and 0.969 respectively. As a result, no significant difference was found in the dolphin encounter rates between the baseline period and the cumulative quarters in the impact phase.
4.17 To facilitate the comparison with the AFCD long-term monitoring results, the encounter rates were also calculated for the present quarter (December 2013 to February 2014) using both primary and secondary survey effort. The encounter rates of sightings (STG) and dolphins (ANI) in WL were 15.7 sightings and 58.5 dolphins per 100 km of survey effort respectively.
Group size
4.18 Group size of Chinese White Dolphins ranged from 1-17 individuals per group in WL survey area between December 2013 to February 2014. The average dolphin group sizes from these three months were compared with the one deduced from the baseline period in September to November 2011, as shown in Table 4.8. The average dolphin group size in the WL region during December 2013 to February 2014 was higher than than the ones recorded in the 3-month baseline period (Table 4.8). More than half of the dolphin groups were composed of 1-2 dolphins, but there were also 13 groups with more than 5 animals per group, and three groups with more than 10 animals per group. Some of the larger groups were associated with operating purse-seiners.
Table 4.8 Comparison of average dolphin group sizes from
impact monitoring period (December
2013 – February 2014)
and baseline monitoring period (September-November 2011)
|
|
Average Dolphin Group
Size |
|
|
December 2013 to February 2014 |
September – November 2011 |
|
|
West Lantau |
4.03 ± 3.71 (n = 36) |
3.63 ± 2.97 (n = 46) |
4.19 Distribution of dolphins with these 13 larger groups during December 2013 to February 2014 is shown in Figure 3 of Appendix F. These groups were mostly sighted between Kai Kung Shan and Peaked Hill, which were further away from the HKLR09 alignment.
Habitat use
4.20 From December 2013 to February 2014, the most heavily utilized habitats by the dolphins mainly concentrated near Tai O Peninsula, Kai Kung Shan, Peaked Hill and Fan Lau (Figures 4a and 4b of Appendix F). However, it should be noted that the amount of survey effort collected in each grid during the three-month period was fairly low (6 units of survey effort for most grids), and therefore the habitat use pattern derived from the three-month dataset should be treated with caution. A more complete picture of dolphin habitat use pattern will be presented when more survey effort for each grid will be collected throughout the impact phase monitoring programme.
4.21 When compared with the habitat use pattern recorded during the baseline period, it appears that dolphin densities were much lower between the HKLR09 alignment and Tai O Peninsula during the present impact phase monitoring period (Figure 5 of Appendix F).
Mother-calf pairs
4.22 During the three-month impact phase monitoring period, only five unspotted juveniles (UJ) were sighted in WL survey area. These young calves comprised only 3.4% of all animals sighted, which was much lower to the percentage recorded during the baseline monitoring period (6.6%).
4.23 The occurrence of these young calves were scattered between Kai Kung Shan and Peaked Hill, which was in stark contrast to the baseline period when calf occurrence was more frequent near Tai O Peninsula (Figure 6 of Appendix F).
Activities and associations
with fishing boats
4.24 A total of five dolphin sightings were associated with feeding respectively during the three-month impact monitoring period, comprising of 13.8% of the total number of dolphin sightings. This percentage was similar to the percentage recorded during the baseline period (13.0%). Only one of the 36 sightings was associated with socializing activity.
4.25 Distribution of dolphins engaged in the feeding activities during the three-month study period is shown in Figure 7 of Appendix F. The sightings associated with feeding activities were scattered between the bridge alignment and Kai Kung Shan, with no particular concentration. This distribution pattern was similar to the baseline period, when most feeding activities were concentrated in the middle portion of the survey area between Tai O Peninsula and Kai Kung Shan (Figure 7 of Appendix F).
4.26 During the three-month period, three dolphin groups were associated
with an operating purse-seiner, while one
group of two dolphins was associated with an operating gill-netter, together comprising of 11.1% of all dolphin groups. This was much lower than the percentage recorded in baseline period
(6.5%).
Summary of
photo-identification works
4.27 From December 2013 to February 2014, over 2,000 digital photographs of Chinese White Dolphins were taken during the impact phase monitoring surveys for the photo-identification work.
4.28 In total, 42 individuals sighted 73 times altogether were identified (see summary table in Appendix III of Appendix F and photographs of identified individuals in Appendix IV of Appendix F. Most identified individuals were sighted only once or twice during the three-month period, but five individuals (NL128, WL93, WL109, WL152 and WL180) were sighted thrice, while two individuals (WL91 and WL25) were sighted four and six times respectively.
4.29 During the three-month period, four recognizable females, including NL33, NL188, NL264 and WL171, were sighted to be accompanied with her calf during her re-sighting. Notably, the first three individuals spent most of their time in North Lantau waters in the past, and therefore only a very small number of dolphins that focused their range use in West Lantau waters were mother-calf pairs, similar to the results in previous monitoring quarters.
Individual range use
4.30 Ranging patterns of the 42 individuals identified during the three-month study period were determined by fixed kernel method, and are shown in Appendix V of Appendix F.
4.31 Among these 42 individuals, six of them (NL33, NL188, NL226, NL264, NL288 and NL296) occurred primarily in North Lantau and ventured into West Lantau during the three-month period, while two other individuals (NL156 and WL179) split their time between North and West Lantau waters. The other 34 individuals centered their range use in West Lantau waters. (Appendix V of Appendix F)
4.32 Notably, the ranging patterns of a few individuals (e.g. SL44, WL182) do not overlap with the HKLR09 alignment at all, but mostly located around the southwestern side of Lantau Island (Appendix V of Appendix F). Therefore, it is unlikely that the impact of HKLR09 construction activities will affect their range use during the impact phase.
Conclusion
4.33 During this quarter of dolphin monitoring, no adverse impact from the activities of the HKLR09 construction project on Chinese White Dolphins was noticeable from general observations, and the dolphin occurrence in West Lantau survey area remained the same as in the baseline period.
4.34 Nevertheless, dolphin usage in WL region should be continuously monitored, to further examine whether it has been affected by the on-going construction activities in relation to the HZMB works.
4.35 Additional land-based dolphin behavior and movement monitoring was conducted on 22nd and 27th January 2014 in the reporting period. The progress of the monitoring is summarized in the Table 4.9.
Table 4.9 Progress
Record of Additional Land-based Dolphin Behaviour and
Movement Monitoring in January
2014
|
Date |
Time |
Weather |
Number
of Staff |
Number
of Dolphin Sighting |
|
|
Beaufort |
Visibility |
||||
|
22/01/2014 |
09:05 - 14:32 |
2 |
2.5 |
3 |
1 |
|
27/01/2014 |
08:54 - 14:58 |
1-3 |
2.5 |
3 |
4 |
4.36
Detailed
monitoring methodology and results will be provided in a separate report after
the completion of full set of additional land-based dolphin behavior and
movement monitoring.
4.37
The
Contractor was advised to minimize the wastes generated through the recycling
or reusing. All mitigation measures stipulated in approved waste management
plan shall be fully implemented.
4.38
The
amount of wastes generated by the activities of the Contract during the
reporting month is shown in Appendix J.